Solve for $x$ and $y$ using substitution. ${3x+6y = -3}$ ${x = -6y+11}$
Explanation: Since $x$ has already been solved for, substitute $-6y+11$ for $x$ in the first equation. ${3}{(-6y+11)}{+ 6y = -3}$ Simplify and solve for $y$ $-18y+33 + 6y = -3$ $-12y+33 = -3$ $-12y+33{-33} = -3{-33}$ $-12y = -36$ $\dfrac{-12y}{{-12}} = \dfrac{-36}{{-12}}$ ${y = 3}$ Now that you know ${y = 3}$ , plug it back into $\thinspace {x = -6y+11}\thinspace$ to find $x$ ${x = -6}{(3)}{ + 11}$ $x = -18 + 11$ ${x = -7}$ You can also plug ${y = 3}$ into $\thinspace {3x+6y = -3}\thinspace$ and get the same answer for $x$ : ${3x + 6}{(3)}{= -3}$ ${x = -7}$